Carbonate compounds are currently used as electrolyte solvents for non-aqueous batteries containing electrodes made from alkali metals, alkaline earth metals, or compounds comprising these metals, for example lithium ion batteries. Current lithium ion battery electrolyte solvents typically contain one or more linear carbonates, such as ethyl methyl carbonate, dimethyl carbonate, or diethyl carbonate; and a cyclic carbonate, such as ethylene carbonate. However, at cathode potentials above 4.35 V these electrolyte solvents can decompose, which can result in a loss of battery performance.
Various approaches have been investigated to overcome the limitations of commonly used non-aqueous electrolyte solvents. Although these electrolyte solvents can be used in lithium ion batteries having high potential cathodes, specifically at voltages greater than about 4.35 V, such as LiCoO2 or LiNixMnyCozO2 where x+y+z is about 1, charged to cathode potentials higher than the standard 4.1 to 4.25 V range in order to access higher capacity, cycling performance can be limited, particularly at high temperatures.
A need remains for electrolyte solvents, and compositions thereof, that will have improved performance at high temperature when used in a lithium ion battery, particularly such a battery that operates with a high potential cathode (i.e. up to about 5 V).